Local crystallization in amorphous microwires of PrDyFeCoB induced by a single laser pulse

Areas containing soft ferromagnetic phases of (PrDy)$_{1}$(FeCoB)$_{2}$, (PrDy)$_{2}$(FeCoB)$_{1}$, (PrDy)$_{1}$(FeCoB)$_{4}$B$_{1}$, and the main magnetic phase of (PrDy)$_{2}$(FeCoB)$_{14}$B$_{1}$ were found in amorphous microwires made from PrDyFeCoB treated by a single laser pulse with the energy of 1 mJ, duration of 120 ns, and the wavelength of 1040 nm. The difference between lengthy annealing of the whole sample in vacuum and local laser heating of the part of its surface is that annealing produces the grains of the phase (PrDy)$_2$(FeCoB)$_{14}$B$_1$ with the size of 800 nm, while after laser irradiation the grain size of this phase is 10–20 nm. Interleaving crystalline zones along the microwire’s axis gives it the magnetically modulated structure with the perpendicular component of the magnetization. Local magnetic hysteresis loops obtained using a Kerr microscope in the areas subject to laser radiation demonstrate the magnetic anisotropy field of 500 Oe, which is larger than 10 Oe observed in the non-treated areas.